Abstract: - Gas distribution network of some cold regions of Iran face pressure drop and accordingly gas cut off in winters. Most of time, increasing consumption is stated as the main reason of this problem while the author believes that this is not the only reason. Non-optimized gas distribution network is another important reason that can cause pressure drop and gas cut off. For this purpose, a gas distribution network in a village called Bawariz, near the Sanandaj city, Iran, is optimized using a developed optimization algorithm. The results reveal that most of pipe sizes (more than 90%) are over designed. Non-optimized network increases cost of network implementation and also influences gas distribution and as a result gas delivery.